Some questions for Monkhorst-Pack's paper

I am trying to figure out how Monkhorst-Pack grits work, but I cannot repeat some results in their paper. (H. J. Monkhorst and J. D. Pack, Special points for Brillouin-zone integrations, 13, 5188, 1976)

1. In equation (9), when [itex]|R^b_j - R^a_j|=p[/itex], which is not multiples of q, [itex]W^{ab}_j(q) = e^{-ip\pi/q}(-1)^p[/itex] according to my calculation. Only when r = 0, 1 ,2 ...,q, [itex]W^{ab}_j(q)=0[/itex].
2. In equation (19), I got [itex]\epsilon_{BZ} =\frac{8\pi^3}{v} \sum_{m>1}f_mS_{m1}(q)[/itex]
3. In equation A7, if q=4, P(q)=2, but some software gave a value of 10 when q=4 for FCC point group.